Building Instructions

Start by building the Baseball Batter.
Click the picture for building instructions.

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Use the two longest wires to connect the two motors
to ports B and C on the NXT as shown below (do not cross
the wires).

Pitching Machine and Batter Programming

Use the program
Pitch_and_Bat for your Pitching Machine and Batter. This program
is just like the Baseball_Bat program for the
Baseball Batter
project with one Move block added to spin the wheels of the pitching
machine.

How to
Use the Pitching Machine and Batter

Arrange the pitching
machine and
batter on the floor as shown in the last picture above. The
balls should be aimed at the ultrasonic sensor.

Place one of the plastic
balls that come with the NXT set on the back end of the ramp.
The ramp is slightly downhill towards the wheels, so the ball should
roll slowly towards the spinning wheels and then get launched
through them towards the batter. When the
batter's ultrasonic sensor sees the ball at the programmed distance (14 inches), it will
swing to hit the ball.

If you have problems
with the ball running into the long wires, you can put a piece of
paper over them as shown below.

Challenges

Experiment with
different distances and angles for the pitching machine to see how
it affects the hit. Unfortunately you are limited by the
length of the wires, but see how you can make the best of it.
For a building challenge, try separating the NXT brick from the
batter and placing it somewhere in between the pitching machine and
the batter to make better use of the available wire lengths.

Even with the pitching
machine and batter in the same place, not all balls will be hit in
the same direction. For example, sometimes the hit will come
back and hit the pitching machine, but sometimes it will go to one
side and make it past. In fact, sometimes the results are not
even close to being the same. If the motors and the program
are doing exactly the same thing every time, what do think causes
different balls to be hit differently? Well, if you like
reading complicated articles with lots of big words, try reading
about Chaos
Theory. If you think baseball looks random when people
play it, just think, even robots can't play it consistently!